Efficient Mesoporous MgO/g-C3N4 for Heavy Metal Uptake: Modeling Process and Adsorption Mechanism

Synthesis of Metal-Organic Framework-Based ZIF-8@ZIF-67 Nanocomposites for Antibiotic Decomposition and Antibacterial Activities

Toxic antibiotic effluents and antibiotic-resistant bacteria constitute a threat to global health. So, scientists are investigating high-performance materials for antibiotic decomposition and antibacterial activities. In this novel research work, we have successfully designed ZIF-8@ZIF-67 nanocomposites via sol-gel and solvothermal approaches. The ZIF-8@ZIF-67 nanocomposite is characterized by various techniques that exhibit superior surface area enhancement, charge separation, and high light absorption performance. Yet, ZIF-8 has high adsorption rates and active sites, while ZIF-67 has larger pore volume and efficient adsorption and reaction capabilities, demonstrating that the ZIF-8@ZIF-67 nanocomposite outperforms pristine ZIF-8 and ZIF-67. Compared with pristine ZIF-8 and ZIF-67, the most active 6ZIF-67@ZIF-8 nanocomposite showed higher decomposition efficacy for ciprofloxacin (65%), levofloxacin (54%), and ofloxacin (48%). Scavenger experiments confirmed that •OH, •O2-, and h+ are the most active species for the decomposition of ciprofloxacin (CIP), levofloxacin (LF), and ofloxacin (OFX), respectively. In addition, the 6ZIF-67/ZIF-8 nanocomposite suggested its potential applications in Escherichia coli for growth inhibition zone, antibacterial activity, and decreased viability. Moreover, the stability test and decomposition pathway of CIP, LF, and OFX were also proposed. Finally, our study aims to enhance the efficiency and stability of ZIF-8@ZIF-67 nanocomposite and potentially enable its applications in antibiotic decomposition, antibacterial activities, and environmental remediation.

Uptake of BF Dye from the Aqueous Phase by CaO-g-C3N4 Nanosorbent: Construction, Descriptions, and Recyclability

Removing organic dyes from contaminated wastewater resulting from industrial effluents with a cost-effective approach addresses a major global challenge. The adsorption technique onto carbon-based materials and metal oxide is one of the most effective dye removal procedures. The current work aimed to evaluate the application of calcium oxide-doped carbon nitride nanostructures (CaO-g-C3N4) to eliminate basic fuchsine dyes (BF) from wastewater. CaO-g-C3N4 nanosorbent were obtained via ultrasonication and characterized by scanning electron microscopy, X-ray diffraction, TEM, and BET. The TEM analysis reveals 2D nanosheet-like nanoparticle architectures with a high specific surface area (37.31 m2/g) for the as-fabricated CaO-g-C3N4 nanosorbent. The adsorption results demonstrated that the variation of the dye concentration impacted the elimination of BF by CaO-C3N4 while no effect of pH on the removal of BF was observed. Freundlich isotherm and Pseudo-First-order adsorption kinetics models best fitted BF adsorption onto CaO-g-C3N4. The highest adsorption capacity of CaO-g-C3N4 for BF was determined to be 813 mg. g−1. The adsorption mechanism of BF is related to the π-π stacking bridging and hydrogen bond, as demonstrated by the FTIR study. CaO-g-C3N4 nanostructures may be easily recovered from solution and were effectively employed for BF elimination in at least four continuous cycles. The fabricated CaO-g-C3N4 adsorbent display excellent BF adsorption capacity and can be used as a potential sorbent in wastewater purification.